The present invention relates to the manufacture of magnetic and optical recording media and in particular to a method and apparatus for applying lubrication to the surface of the media.
In a conventional contact start-stop (CSS) operation of a hard disk drive, the magnetic head slides against the disk surface when the disk is spun up and down. To protect the magnetic head and the disk surface from the frictional effects of CSS operations, the disk surface is lubricated in fabrication.
FIG. 1 illustrates a prior art apparatus 100 for lubing disks. A linear stage 102 lowers a mandrel 104 with a conventional disk 106 resting thereon into a lubrication tank 108 filled with lubrication solution 110. The disk is then lifted out of the solution or alternatively the lubrication solution is drained, leaving behind a thin (1-10 nm) layer of lubrication on the surface of the disk. Disk 106 has, e.g., an inner diameter (ID) 114 of 25 mm and an outer diameter (OD) of 95 mm. An arrow 116 indicates the travel of mandrel 104 into and out of lubrication tank 108. Mandrel 104 includes a notch 112 where ID 114 of disk 106 rests upon. As FIG. 1 illustrates, lubrication solution 118 often collects around notch 112 and deposits excessive lubricant on disk 106 due to the improper drainage. While excess lubricant is a reliability and performance concern for media, the amount deposited on disk 106 is acceptable because it affects only a small percentage of the total area of disk 106.
FIG. 2 illustrates the use of conventional apparatus 100 to apply lubrication to a disk 122 which has a small form factor. Disk 122 has, e.g., an ID 124 of 7 mm and an OD of 27.4 mm. Lubrication solution 118 again collects around notch 112. Excessive lubricant on disk 122 near ID 124 produces an undesirable result. Compared to disk 106, excessive lubrication 118 is of greater concern for disk 122 because disk 122 has a smaller surface area. Thus a greater portion of the surface of disk 122 will have excess lubrication 118 deposited thereon then will disk 106. Disk 122 is also more likely to sway and tip over as it hangs from mandrel 104 because disk 122 is lighter. Furthermore, as the lubrication solution moves across the surface of the disk, surface tension imbalances may cause the disk to tilt. This phenomenon can slow down production and cause non-uniformity in disk lubrication.
Thus, what is needed is a system that lubricates a small form factor disk without excessive lubrication around its inner diameter and unwanted movement of the disk during processing.
A system for processing a disk includes a tank, a base adjacent to the tank, a rotary actuator mounted to the base, and an end-effector mounted to the rotary actuator. The end-effector includes a plurality of fingers and an actuator linked to at least one finger. The actuator closes the fingers so they can be inserted into an inner diameter of the disk. The actuator opens the fingers so they can grip the inner diameter of the disk. Once the fingers have gripped the disk, the rotary actuator rotates the end-effector to a position above the tank. The disk can be brought down into the tank or the tank can be brought up to place the disk within the tank. The tank is then filled with a processing liquid to process the disk.